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United States Patent | 5,673,391 |
Webb ,   et al. | September 30, 1997 |
Retry trap in the processor system detects the occurrence of a hardware retry during a millicode routine. In operation, millicode resets the retry trap to "O" at the start of a millicode sequence that is sensitive to a retry operation being at some stage of the millicode sequence. The millicode routine tests the retry latch state at one or more points in the sequence to determine if a retry has occurred since the start of the sequence, which is sensitive to a retry operation. The action taken in response to a determination that a retry operation has occurred depends upon the type of potential damage to the system state as a result of the occurrence of the retry operation during the millicode sequence.
Inventors: | Webb; Charles Franklin (Poughkeepsie, NY); Farrell; Mark Steven (Pleasant Valley, NY); Swaney; Scott Barnett (Catskill, NY) |
Assignee: | International Business Machines Corporation (Armonk, NY) |
Appl. No.: | 414977 |
Filed: | March 31, 1995 |
Current U.S. Class: | 714/20; 712/42; 712/200; 714/23 |
Intern'l Class: | G06F 011/34 |
Field of Search: | 395/182.13,182.14,182.15,182.19,182.21,184.01,185.02,376,800 364/260.8,262.4,262.6,262.8,266.5 |
4641305 | Feb., 1987 | Joyce et al. | |
4755995 | Jul., 1988 | Anderson et al. | |
4851995 | Jul., 1989 | Hsu et al. | |
4901233 | Feb., 1990 | Liptay. | |
4999837 | Mar., 1991 | Reynolds et al. | |
5129080 | Jul., 1992 | Smith. | |
5226164 | Jul., 1993 | Nadas et al. | |
5280593 | Jan., 1994 | Bullions, III et al. | |
5293613 | Mar., 1994 | Hayden et al. | |
5307504 | Apr., 1994 | Robinson et al. | 364/200. |
5325520 | Jun., 1994 | Nguyen et al. | |
Foreign Patent Documents | |||
56-9846 | Jan., 1981 | JP | . |
57-48145 | Mar., 1982 | JP | . |
9178547 | Oct., 1984 | JP | . |
62-77650 | Apr., 1987 | JP | . |
4181331 | Jun., 1992 | JP | . |
4195433 | Jul., 1992 | JP | . |
IBM/TDB vol. 35 No. 4A Sep. 1992 -Milli-Code: Bullions, Chang, Meltzer, Nadas, Pedersen. |